Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 411 insertions, 0 deletions

diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
new file mode 100644
index 000000000..5d6b0dd4d
--- /dev/null
+++ b/drivers/tty/Kconfig
@@ -0,0 +1,411 @@
+# SPDX-License-Identifier: GPL-2.0
+config TTY
+	bool "Enable TTY" if EXPERT
+	default y
+	help
+	  Allows you to remove TTY support which can save space, and
+	  blocks features that require TTY from inclusion in the kernel.
+	  TTY is required for any text terminals or serial port
+	  communication. Most users should leave this enabled.
+
+if TTY
+
+config VT
+	bool "Virtual terminal" if EXPERT
+	select INPUT
+	default y if !UML
+	help
+	  If you say Y here, you will get support for terminal devices with
+	  display and keyboard devices. These are called "virtual" because you
+	  can run several virtual terminals (also called virtual consoles) on
+	  one physical terminal. This is rather useful, for example one
+	  virtual terminal can collect system messages and warnings, another
+	  one can be used for a text-mode user session, and a third could run
+	  an X session, all in parallel. Switching between virtual terminals
+	  is done with certain key combinations, usually Alt-<function key>.
+
+	  The setterm command ("man setterm") can be used to change the
+	  properties (such as colors or beeping) of a virtual terminal. The
+	  man page console_codes(4) ("man console_codes") contains the special
+	  character sequences that can be used to change those properties
+	  directly. The fonts used on virtual terminals can be changed with
+	  the setfont ("man setfont") command and the key bindings are defined
+	  with the loadkeys ("man loadkeys") command.
+
+	  You need at least one virtual terminal device in order to make use
+	  of your keyboard and monitor. Therefore, only people configuring an
+	  embedded system would want to say N here in order to save some
+	  memory; the only way to log into such a system is then via a serial
+	  or network connection.
+
+	  If unsure, say Y, or else you won't be able to do much with your new
+	  shiny Linux system :-)
+
+config CONSOLE_TRANSLATIONS
+	depends on VT
+	default y
+	bool "Enable character translations in console" if EXPERT
+	help
+	  This enables support for font mapping and Unicode translation
+	  on virtual consoles.
+
+config VT_CONSOLE
+	bool "Support for console on virtual terminal" if EXPERT
+	depends on VT
+	default y
+	help
+	  The system console is the device which receives all kernel messages
+	  and warnings and which allows logins in single user mode. If you
+	  answer Y here, a virtual terminal (the device used to interact with
+	  a physical terminal) can be used as system console. This is the most
+	  common mode of operations, so you should say Y here unless you want
+	  the kernel messages be output only to a serial port (in which case
+	  you should say Y to "Console on serial port", below).
+
+	  If you do say Y here, by default the currently visible virtual
+	  terminal (/dev/tty0) will be used as system console. You can change
+	  that with a kernel command line option such as "console=tty3" which
+	  would use the third virtual terminal as system console. (Try "man
+	  bootparam" or see the documentation of your boot loader (lilo or
+	  loadlin) about how to pass options to the kernel at boot time.)
+
+	  If unsure, say Y.
+
+config VT_CONSOLE_SLEEP
+	def_bool y
+	depends on VT_CONSOLE && PM_SLEEP
+
+config VT_HW_CONSOLE_BINDING
+	bool "Support for binding and unbinding console drivers"
+	depends on VT
+	help
+	  The virtual terminal is the device that interacts with the physical
+	  terminal through console drivers. On these systems, at least one
+	  console driver is loaded. In other configurations, additional console
+	  drivers may be enabled, such as the framebuffer console. If more than
+	  1 console driver is enabled, setting this to 'y' will allow you to
+	  select the console driver that will serve as the backend for the
+	  virtual terminals.
+
+	  See <file:Documentation/driver-api/console.rst> for more
+	  information. For framebuffer console users, please refer to
+	  <file:Documentation/fb/fbcon.rst>.
+
+config UNIX98_PTYS
+	bool "Unix98 PTY support" if EXPERT
+	default y
+	help
+	  A pseudo terminal (PTY) is a software device consisting of two
+	  halves: a master and a slave. The slave device behaves identical to
+	  a physical terminal; the master device is used by a process to
+	  read data from and write data to the slave, thereby emulating a
+	  terminal. Typical programs for the master side are telnet servers
+	  and xterms.
+
+	  Linux has traditionally used the BSD-like names /dev/ptyxx for
+	  masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
+	  has a number of problems. The GNU C library glibc 2.1 and later,
+	  however, supports the Unix98 naming standard: in order to acquire a
+	  pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
+	  terminal is then made available to the process and the pseudo
+	  terminal slave can be accessed as /dev/pts/<number>. What was
+	  traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
+
+	  All modern Linux systems use the Unix98 ptys.  Say Y unless
+	  you're on an embedded system and want to conserve memory.
+
+config LEGACY_PTYS
+	bool "Legacy (BSD) PTY support"
+	default y
+	help
+	  A pseudo terminal (PTY) is a software device consisting of two
+	  halves: a master and a slave. The slave device behaves identical to
+	  a physical terminal; the master device is used by a process to
+	  read data from and write data to the slave, thereby emulating a
+	  terminal. Typical programs for the master side are telnet servers
+	  and xterms.
+
+	  Linux has traditionally used the BSD-like names /dev/ptyxx
+	  for masters and /dev/ttyxx for slaves of pseudo
+	  terminals. This scheme has a number of problems, including
+	  security.  This option enables these legacy devices; on most
+	  systems, it is safe to say N.
+
+config LEGACY_PTY_COUNT
+	int "Maximum number of legacy PTY in use"
+	depends on LEGACY_PTYS
+	range 0 256
+	default "256"
+	help
+	  The maximum number of legacy PTYs that can be used at any one time.
+	  The default is 256, and should be more than enough.  Embedded
+	  systems may want to reduce this to save memory.
+
+	  When not in use, each legacy PTY occupies 12 bytes on 32-bit
+	  architectures and 24 bytes on 64-bit architectures.
+
+config LEGACY_TIOCSTI
+	bool "Allow legacy TIOCSTI usage"
+	default y
+	help
+	  Historically the kernel has allowed TIOCSTI, which will push
+	  characters into a controlling TTY. This continues to be used
+	  as a malicious privilege escalation mechanism, and provides no
+	  meaningful real-world utility any more. Its use is considered
+	  a dangerous legacy operation, and can be disabled on most
+	  systems.
+
+	  Say Y here only if you have confirmed that your system's
+	  userspace depends on this functionality to continue operating
+	  normally.
+
+	  Processes which run with CAP_SYS_ADMIN, such as BRLTTY, can
+	  use TIOCSTI even when this is set to N.
+
+	  This functionality can be changed at runtime with the
+	  dev.tty.legacy_tiocsti sysctl. This configuration option sets
+	  the default value of the sysctl.
+
+config LDISC_AUTOLOAD
+	bool "Automatically load TTY Line Disciplines"
+	default y
+	help
+	  Historically the kernel has always automatically loaded any
+	  line discipline that is in a kernel module when a user asks
+	  for it to be loaded with the TIOCSETD ioctl, or through other
+	  means.  This is not always the best thing to do on systems
+	  where you know you will not be using some of the more
+	  "ancient" line disciplines, so prevent the kernel from doing
+	  this unless the request is coming from a process with the
+	  CAP_SYS_MODULE permissions.
+
+	  Say 'Y' here if you trust your userspace users to do the right
+	  thing, or if you have only provided the line disciplines that
+	  you know you will be using, or if you wish to continue to use
+	  the traditional method of on-demand loading of these modules
+	  by any user.
+
+	  This functionality can be changed at runtime with the
+	  dev.tty.ldisc_autoload sysctl, this configuration option will
+	  only set the default value of this functionality.
+
+source "drivers/tty/serial/Kconfig"
+
+config SERIAL_NONSTANDARD
+	bool "Non-standard serial port support"
+	depends on HAS_IOMEM
+	help
+	  Say Y here if you have any non-standard serial boards -- boards
+	  which aren't supported using the standard "dumb" serial driver.
+	  This includes intelligent serial boards such as
+	  Digiboards, etc. These are usually used for systems that need many
+	  serial ports because they serve many terminals or dial-in
+	  connections.
+
+	  Note that the answer to this question won't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about non-standard serial boards.
+
+	  Most people can say N here.
+
+config MOXA_INTELLIO
+	tristate "Moxa Intellio support"
+	depends on SERIAL_NONSTANDARD && PCI
+	select FW_LOADER
+	help
+	  Say Y here if you have a Moxa Intellio multiport serial card.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called moxa.
+
+config MOXA_SMARTIO
+	tristate "Moxa SmartIO support v. 2.0"
+	depends on SERIAL_NONSTANDARD && PCI && HAS_IOPORT
+	help
+	  Say Y here if you have a Moxa SmartIO multiport serial card and/or
+	  want to help develop a new version of this driver.
+
+	  This is upgraded (1.9.1) driver from original Moxa drivers with
+	  changes finally resulting in PCI probing.
+
+	  This driver can also be built as a module. The module will be called
+	  mxser. If you want to do that, say M here.
+
+config N_HDLC
+	tristate "HDLC line discipline support"
+	depends on SERIAL_NONSTANDARD
+	help
+	  Allows synchronous HDLC communications with tty device drivers that
+	  support synchronous HDLC.
+
+	  This driver can be built as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  The module will be called n_hdlc. If you want to do that, say M
+	  here.
+
+config PPC_EPAPR_HV_BYTECHAN
+	bool "ePAPR hypervisor byte channel driver"
+	depends on PPC
+	select EPAPR_PARAVIRT
+	help
+	  This driver creates /dev entries for each ePAPR hypervisor byte
+	  channel, thereby allowing applications to communicate with byte
+	  channels as if they were serial ports.
+
+config PPC_EARLY_DEBUG_EHV_BC
+	bool "Early console (udbg) support for ePAPR hypervisors"
+	depends on PPC_EPAPR_HV_BYTECHAN=y
+	help
+	  Select this option to enable early console (a.k.a. "udbg") support
+	  via an ePAPR byte channel.  You also need to choose the byte channel
+	  handle below.
+
+config PPC_EARLY_DEBUG_EHV_BC_HANDLE
+	int "Byte channel handle for early console (udbg)"
+	depends on PPC_EARLY_DEBUG_EHV_BC
+	default 0
+	help
+	  If you want early console (udbg) output through a byte channel,
+	  specify the handle of the byte channel to use.
+
+	  For this to work, the byte channel driver must be compiled
+	  in-kernel, not as a module.
+
+	  Note that only one early console driver can be enabled, so don't
+	  enable any others if you enable this one.
+
+	  If the number you specify is not a valid byte channel handle, then
+	  there simply will be no early console output.  This is true also
+	  if you don't boot under a hypervisor at all.
+
+config GOLDFISH_TTY
+	tristate "Goldfish TTY Driver"
+	depends on GOLDFISH
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	help
+	  Console and system TTY driver for the Goldfish virtual platform.
+
+config GOLDFISH_TTY_EARLY_CONSOLE
+	bool
+	default y if GOLDFISH_TTY=y
+	select SERIAL_EARLYCON
+
+config N_GSM
+	tristate "GSM MUX line discipline support (EXPERIMENTAL)"
+	depends on NET
+	help
+	  This line discipline provides support for the GSM MUX protocol and
+	  presents the mux as a set of 61 individual tty devices.
+
+config NOZOMI
+	tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
+	depends on PCI
+	help
+	  If you have a HSDPA driver Broadband Wireless Data Card -
+	  Globe Trotter PCMCIA card, say Y here.
+
+	  To compile this driver as a module, choose M here, the module
+	  will be called nozomi.
+
+config MIPS_EJTAG_FDC_TTY
+	bool "MIPS EJTAG Fast Debug Channel TTY"
+	depends on MIPS_CDMM
+	help
+	  This enables a TTY and console on the MIPS EJTAG Fast Debug Channels,
+	  if they are present. This can be useful when working with an EJTAG
+	  probe which supports it, to get console output and a login prompt via
+	  EJTAG without needing to connect a serial cable.
+
+	  TTY devices are named e.g. ttyFDC3c2 (for FDC channel 2 of the FDC on
+	  CPU3).
+
+	  The console can be enabled with console=fdc1 (for FDC channel 1 on all
+	  CPUs). Do not use the console unless there is a debug probe attached
+	  to drain the FDC TX FIFO.
+
+	  If unsure, say N.
+
+config MIPS_EJTAG_FDC_EARLYCON
+	bool "Early FDC console"
+	depends on MIPS_EJTAG_FDC_TTY
+	help
+	  This registers a console on FDC channel 1 very early during boot (from
+	  MIPS arch code). This is useful for bring-up and debugging early boot
+	  issues.
+
+	  Do not enable unless there is a debug probe attached to drain the FDC
+	  TX FIFO.
+
+	  If unsure, say N.
+
+config MIPS_EJTAG_FDC_KGDB
+	bool "Use KGDB over an FDC channel"
+	depends on MIPS_EJTAG_FDC_TTY && KGDB
+	default y
+	help
+	  This enables the use of KGDB over an FDC channel, allowing KGDB to be
+	  used remotely or when a serial port isn't available.
+
+config MIPS_EJTAG_FDC_KGDB_CHAN
+	int "KGDB FDC channel"
+	depends on MIPS_EJTAG_FDC_KGDB
+	range 2 15
+	default 3
+	help
+	  FDC channel number to use for KGDB.
+
+config NULL_TTY
+	tristate "NULL TTY driver"
+	help
+	  Say Y here if you want a NULL TTY which simply discards messages.
+
+	  This is useful to allow userspace applications which expect a console
+	  device to work without modifications even when no console is
+	  available or desired.
+
+	  In order to use this driver, you should redirect the console to this
+	  TTY, boot the kernel with console=ttynull, or enable
+	  NULL_TTY_DEFAULT_CONSOLE.
+
+	  If unsure, say N.
+
+config NULL_TTY_DEFAULT_CONSOLE
+	bool "Support for console on ttynull"
+	depends on NULL_TTY=y && !VT_CONSOLE
+	help
+	  Say Y here if you want the NULL TTY to be used as a /dev/console
+	  device by default.
+
+	  For example, it might be useful to prevent a VT-less kernel from
+	  writing the system log to a random device connected to the serial
+	  port.
+
+	  Another console driver still might get preferred via the command
+	  line, SPCR, or the device tree.
+
+	  If unsure, say N.
+
+config VCC
+	tristate "Sun Virtual Console Concentrator"
+	depends on SUN_LDOMS
+	help
+	  Support for Sun logical domain consoles.
+
+source "drivers/tty/hvc/Kconfig"
+
+config RPMSG_TTY
+	tristate "RPMSG tty driver"
+	depends on RPMSG
+	help
+	  Say y here to export rpmsg endpoints as tty devices, usually found
+	  in /dev/ttyRPMSGx.
+	  This makes it possible for user-space programs to send and receive
+	  rpmsg messages as a standard tty protocol.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called rpmsg_tty.
+
+endif # TTY
+
+source "drivers/tty/serdev/Kconfig"